Thermal conductivity of Taylor phase T-Al73Mn27 complex metallic alloy

Abstract

Thermal conductivity coefficient, κ of Taylor phase T-Al73Mn27 complex metallic alloy with giant unit cell has been studied in the temperature interval from 2 K to 300 K. κ is relatively small in magnitude (comparable to that of thermal insulators), have a slope-change at about 50 K and increases up to 300 K. Such a low κ originates in complex structure: aperiodic in short length scale, that leads to frequent electron scattering and consequent low electron contribution to the thermal conductivity, while large lattice constant defines a small Brillouin zone that enhances umklapp scattering of extended phonons, and suppressing lattice thermal conductivity. Above ~100 K hopping of localized lattice vibrations gives an additional heat-carrying channel.